This invention relates to polyether urethane polymers and to a process for their preparation.
Urethane urea polymers prepared using copolyether glycols [copolymers of tetrahydrofuran (THF) and ethylene oxide (EO)] as one of the starting materials are well known. Preparation of such a polymer is shown in U.S. Pat. No. 3,425,999 to Axelrood and Lajiness, and involves the reaction of a THF/EO copolymer with an organic polyisocyanate to form a prepolymer, and the subsequent reaction of the prepolymer with an amine chain-extending agent to form a urethane urea polymer. While urethane urea polymers of this type are generally satisfactory for use as elastomers, they have, for certain applications, been found deficient in their resistance to degradation on exposure to moisture. Moreover, the amine chain-extending agents preferred for use by Axelrood and Lajiness, dichlorobenzidine and methylene bis(2-chloroaniline), have been designated carcinogens by the U.S. Occupational Safety and Health Administration, and their use is now looked upon with disfavor.